In the mobile communication network including Wideband Code Division Multiple Access (WCDMA) network and Code Division Multiple Access 2000 (CDMA 2000) network, the core network of circuit domain adopts an architecture separating bearer from control; Mobile Switching Center (MSC) has been divided into a Mobile Soft-switch device and a Media Gateway (MGW); and IP bearer network is generally used for a bearer between network entities in the mobile communication network. All IP network has become a trend in the industry.
In the CDMA2000 network, the MSC is divided into a Mobile Switching Center emulation (MSCe) and the MGW; In the WCDMA network, the MSC is divided into an MSC server and the MGW. And in the CDMA2000 network, the network radio access control device is a Base Station Controller (BSC); in the WCDMA network, the network radio access control device is a BSC or Radio Network Controller (RNC).
In the following, the CDMA2000 network is hereinafter described as an example, which is the same as the WCDMA network apart from the different entity names.
FIG. 1 is a schematic diagram illustrating the physical architecture of CDMA2000 network. A Media Resource Function Processor (MRFP) and an MGW are generally combined within one physical entity; an MSCe, MGW, BSC and MRFP/MGW generally access the IP bearer network via routers to implement the interworking between each other.
FIG. 2 is a schematic diagram illustrating the logical architecture of CDMA2000 network. In FIG. 2, the dashed line represents a signaling connection and the solid line represents a traffic data connection.
In FIG. 2, the signaling connection is mainly located between MSCes, between MSCe and MGW, and between MSCe and BSC; the traffic data connection is mainly located between BSC and MGW, and between MGWs, and the data connection between BSCs is implemented via the MGW.
A procedure of transmitting traffic data in FIG. 2 is hereinafter described. MS1 within the coverage area of BTS11 communicates with MS2 within the coverage area of BTS22. After a signaling interaction, BSC1 teams that the traffic data received from BTS11 will be transmitted to MGW1; then MGW1 learns that the traffic data received from BSC1 will be transmitted to MGW2; and MGW2 learns that the traffic data received from MGW1 will be transmitted to BSC2. As a result, in the traffic plane, after receiving the traffic data sent by MS1, BSC1 sends the traffic data to MGW1 after adding the IP address of MGW1 to the traffic data; MGW1 sends the traffic data to MOW2 after modifying the IP address of MGW1 into the IP address of MGW2; MGW2 sends the traffic data to BSC2 after modifying the IP address of MGW into the IP address of BSC2; at last, BSC2 delivers the traffic data from BTS22 to MS2.
As shown in the above description, signaling and traffic data of CDMA2000 system are all carried by IP. For the traffic data transmitted by IP between BSC and MGW, and between MGWs, the destination IP of traffic data may be directly designated in BSC and the traffic data may be routed according to the IP, since each entity takes IP as its bearer and the media access method is simple. Therefore, the forwarding function of media gateway is of no particular significance, but increases the switch number of an IP packet and wastes the system resource.
At present, a manufacturer of industry provides architecture for combining MSC with BSC device and setting an IP interface, which is shown in FIG. 3. FIG. 3 is a schematic diagram illustrating the physical architecture for combining MSC with BSC. Referring to FIG. 3, although this architecture embodies IP bearer, reduces the switch number of an IP packet and has the advantage of low cost, the operator is unable to select the device of manufacturer having the service advantage and the device of manufacturer having the radio advantage to implement the design with optimization, because the MSC and the BSC device are combined into one device and A-Interface between MSC and BSC is unable to be open.
In addition, combining MSC with BSC device is unable to embody the advantage of separating bearer from control. For example, when bearer is separated from control, an MSCe may manage multiple MGWs, and it is only necessary for upgrading a few site MSCe to add service support; however, it is necessary for upgrading all MSC/BSC combination devices in the case of combining MSC with BSC device, which improves the complexity for maintaining a system and increases the cost for maintaining a system.